The invention relates to a structural member comprising a nut having an extended flange, a center hole and a shoulder formed integrally onto its edge.
A structural member of this type can be used, for example, for distributing the force of a screw or a nut over a larger surface of a body, as shown in the DE 43 42 261 C 2. With this known structural member, the shoulder takes the form of a cavity for accommodating the head of a screw extending through the center hole. A structural member of this type is preferably used for attaching one or several courses of roofing paper or an insulation material to a solid understructure.
The known structural member is not suitable for a frictional connection of rigid structural parts, for example wooden beams for a roof truss or wooden boards for manufacturing furniture.
A workman using this known structural member for screwing together two bodies, for example, must furthermore push the screw through holes in the bodies, must then use a washer and must finally attach a nut to the end of the screw and hold this nut while turning the screw. This type of handling is very cumbersome and time consuming. In addition, the nut and the washer are relatively expensive. The assembly can be simplified by attaching the nut to the washer, e.g. welding it on. However, this further increases the cost of production.
It is an object of the invention to create a structural member of the aforementioned type, which can be mounted faster and easier and is cheaper to produce than a nut and washer that may be welded to it.
This object is solved with the structural member of the present invention in which a shoulder is designed to have an essentially tubular shape with a thread on its inside wall.
According to one advantageous modification of the invention, the structural member is provided with a curvature in the shape of a cylindrical wall, the axis of which extends perpendicular to the symmetry axis of the thread.
The structural member may have a dome-shaped curvature, so that the structural member can be used for screwing together two bodies, for example two hollow tubes or two wooden parts. For this, the connecting elements remain inside the hollow tubes or inside two bores in the wooden parts, such that they are not visible from the outside.
According to another advantageous modification of the invention, the outside wall of the tubular shoulder is shaped suitable for engaging a tool, preferably has a hexagonal shape, so that a tool can be used to screw a threaded bolt into the thread of the structural member.
Another variant furthermore provides that the shape of the edge of the dome-shaped, curved nut is suitable for a tool engagement and preferably has meandering notches.
The tubular shoulder can be located on the concave side of the curvature for an invisible countersinking of the structural member inside a bore on the front of a rafter when screwing together a wooden beam and a rafter that is planed, for example, on three sides.
Other advantageous modifications of the invention are disclosed herein.
The advantages achieved with the invention in particular are that the structural member can be mounted easier and faster than two separate parts, such as the nut and washer. Furthermore, the production costs are less, for example, than for a nut welded to a washer. In addition, there is no waste because there is no chip-removing processing, which additionally helps lower the costs and protect the environment.
The drawing shows two exemplary embodiments of the invention, which are described in further detail in the following. Shown are in: